Grinding machine



90:. 30, 1930. c. BOOTH 1,787,337

GRINDING MACHINE mm Jan. 28. 1929 2 Sheeta'-She'bt 1 C. BOOTH GRINDING MACHINE Filed Jan. 28, 1929 2 Sheets-Sheet 2 CLEMENT BOOTH,

Patented Dec. 30, 1930 UNITED STATES PATENT OFFICE CLEMENT BOOTH, OF CINCINNATI, OHIO, ASSIGNOR T0 CINCINNATI GRINDERS INCOR- TORATED, OF CINCINNATI, OHIO, A CORPORATION OF OHIO Gamnme macnrivn Application filed January as, 1929. Serial 110. 335,570.

This invention relates to improvements in grinding machines and particularly to improvements in a centerless grinding machine.

In centerless grinders there are two types, the through feed type, wherein the work is passed axially through the grinding throat between the grinding and regulating or control wheels, and the in-feed type wherein the work piece is placed within the grinding throat and the grinding throat contracted or reduced to force the work piece against the grinding wheel to efiect a proper stock removal.

This invention is especially applicable to the latter type of machine.

An object of the invention is to provide a machine for centerless grinding of work pieces having their center of gravity beyond or outside the normal grinding throat.

Another object of the invention is to provide a device for grinding unbalanced work pieces wherein the work pieces are prevented from tilting or canting while being ground or finished within the grinding throat.

These and other objects are attained by the means described herein and disclosed in the accompanying drawings. in which:

Figure 1 is a front elevation of a center less grinder embodying this invention.

Figure-2 is a top plan view of the device shown in Figure 1.-

Figure 3.is an end elevation the device shown in Figure 1 as seen from line 3-3 of Figure 1.

' Figure 4 is a transverse section taken on line 4-4 of Figure 1.

Figure 5 is a sectional view taken on line 5-5 of Figure 4.

Figure 6 is a sectional view taken on line 6-6 of Figure 4.

Figure 7 is an enlarged fragmentary sectional view of the grinding throat taken on line 7-7 of Figure 2. and Figure 4. and.

Figure 8 is an enlarged fragmentary view taken on line 88 of Figure 2.

In the several views just briefly described: one practical embodiment is illustrated and throughout the views like reference characters are used to indicate similar parts. The

reference character A designates the bed having agrinding wheel B fixedly mounted thereon 1n opposltion to an adjustable regulating or control wheel C. The regulatm or control wheel C is carried by a slide D provided wlth ways adapted to slidably contact ways formed on an intermediate slide E.

This slide E is lon 'tudinally movable on ways formed on bed The slides D and E are respectively provided with clamps 10 and 11 for clamping or securing the slide D to slide E and slide E to the bed.

A feed screw F is rotatably swiveled in a bracket 13 carried by the bed and is provided at its outer end with a pilot wheel 14 for rotating said feed screw. The other end of the feed screw is threadedly received in a nut 12 to which a lever 15 is secured. The nut 12 is rotatably journaled in a bearing 16 in the slide D and is provided with collars 17 to prevent axial movement thereof.

Rotation of the pilot wheel 14 will actuate the re ulating wheel toward the grinding wheel or set up purposes and for taking up wheel wear and the like. Swinging of the lever 15 in a counter-clockwise direction partially rotates the nut 12 to feed the regulating or control wheel toward the grinding wheel for forcing the work against the grind ing wheel to effect a stock removal.

A pin 18 is secured to and extends from the lever 15 toward the slide D at a point above the nut 12. A lost motion link 19 having a slot 20 formed therein to provide shoulder 21 is slidably mounted in a bracket 22 secured on the end of slide D. The link 19 is so positioned that the pin 18 is normally within the slot 20 and when the lever 15 is moved in one with a. work rest block 26 which carries a Work rest blade 27 having an inclined top 28 for supporting. a work plece in engagement blade illustrated is provided with a low part 30 and a high part 31 to respectively support the large diameter 32 and small diameter 33 of the work piece 29. It should be noted however, that when straight work pieces are being [ground a straight angled top work rest blade should be used. 1

A clamp member or retaining blade 52 extends into the grinding throat and overlies the work piece 29 to hold the work piece on the work rest blade 27 to prevent canting or tilting of the work piece while it is being ground. The retaining member is pivoted at 53 between the arms and 51, see Figure 7, formed by a recess 49 in' the forward end 48 of a lever 43. By pivoting the retaining blade 52 inthis manner it is free to assume any position necessary to provide a two point contact on the upper surface of the work piece. I

Lugs 54 and 55 are provided at the opposite ends of the retaining blade to form this two point contact. The operative face of the lugs 54 and 55 is inclined as at 56 in Figure 7 oppositely to the inclination of the work rest blade to assist in holding the work piece against the regulating or control wheel during grinding.

he lever 43 is pivoted at 45 to a bracket 46 secured to the work rest block 26 by cap screws 47. The rear end of the lever 43 has secured to it a pin for positioning one end of expansion spring 58 enclosed within a tubular extension 57 on bracket 46. One end of the spring 58 contacts with the lever 43 while the other end of the spring engages an adjustable plug 59 adjustably. carried by the tubular extension 57. Expansion spring 58 yieldingly urges the lever 43 about its pivot 45 and the retaining blade 52 into engagernent with the work piece. This spring. is

suficiently strong to prevent canting or tilting of the work piece on the work rest blade but it does not interfere with the rotation of the work piece by the regulating or control wheel. This. spring 58 also acts on the lever 43'to cause the retaining member 52 to follow up the surface of the work piece as it is being reduced to size by the grinding wheel.

In order to properly position the work piece 29 within the grinding throat an adjustable stop 61 is threaded into the forward face of the bracket 46. A lock nut 62 is provided to secure the stop in adjusted positions.

The block 26 is provided on its rear face with a pair of ears 34 in which the other end of the rock shaft 25 is journaled. Intermediate the ears 34 there is secured to the rock work piece.

meme

- buckle 40. The other end of the turn buckle 40 is provided with threads for receiving right hand threaded stud 41 of the clevis42. Between the arms of this clevis the lever 43 is pivotally secured by means of pivot 44.

Rotation or rocking of the rock shaft 25 in clockwise direction compresses expansion spring 58 through the turn buckle 40 and associated connections.

T he operation ofthe device is as follows: Lever 15 is actuated in a clockwise direction to the position shown in Figure 3 for retracting the regulating wheel C from the grinding wheel. Near the end of the movement of lever 15, pin 18 engages shoulder 21 to shift the link 19 rearwardly and through the lever 24 rocks the rock shaft 25 in a clock-wise direction. This rocking of the shaft 25 actuates the lever 35 and through the adjustable turn buckle 40 partially rotates the lever 43 about its pivot 45 compressing expansion spring 58 and raising the work retaining blade 52 away from the work rest blade 27.. A work piece may now be placed within the grinding throat with its inner edge abutting the stop member 51.

The lever 15 is now actuated in a counter clockwise direction for rotating nut 12 and feeding the regulating 'wheel toward the grinding wheel. This movement of the lever 15 and the pin 18 releases link 19 whereupon the spring 58 expands yieldingly forcing the retaining blade 52 into engagement with the After the lever 15 has been actuated in clockwise direction to feed the regulating wheel toward the grinding wheel the required amount to reduce the work piece to its proper size, the lever is actuated in a clock-wise direction to its original position. Near the end of the return movement, as was described above, the pin 18 engages the shoulder 21 of the link 19 and through the rock shaft 25., connecting levers 24 and 35, and turn buckle 4O rocks the lever 43 about itspivot, raising the retaining blade from the work piece and releasing said work piece so that same can be removed from the grinding throat and a. new unfinished piece inserted.

From the foregoing description, it is believed that the construction and operation'oi the improved device will be thoroughly un-' Particular attention is invited to the fact that with the arrangement of parts here described the supplemental resilient work engagingand positioning member 52 is brought into operative relation to the work at the inception of the inward shifting of the regulating wheel with the result that this member positively engages and urges the work toward the operative surface of the regulating wheel supplementing the gravity action of the angle top work rest blade 28 in this respect. The combined effect of these parts is such as to attain a 'proper frictional engagement between the regulating wheel and work prior to contact of the grinding wheel with the work. This facilitates pre-rotation of the work so that insertion of out of balance parts will be overcome and the parts will be rotated by the regulatin wheel prior to engagement of the grinding wheel therewith, reducing to a.v minimum the liability of formation of a flat or the like on a work piece as might occur if the same were in a condition of rest. when first engaged by the grinding wheel.

It will further .be noted that the construction and operation of the overhead bearing member and the pressure exerted thereby is such as to positively hold the work against tilting on the work rest 28 under influence of gravity and as to properly urge the work piece against the regulating wheel for prerotation of the work, but at the same time the yielding retension of the work is such as to permit free transverse sliding movement of the work on the rest under the influence of the positive engagement of the regulating wheel therewith so t-hat'the work may rise and fall on the angle top blade in the initial irregular form. The steadying member does not in any wayinterfere with the proper rounding up of the work as might occur if a fixed or non-yielding overhead shoe were employed. \Vhat is claimed, is:

1. In a grinding machine. the combination with a pair of opposed grinding and regulating wheels forming a grinding throat betweeu them, of a block within the grinding throatfa work rest blade secured to the block,

a bracket carried by the block, a lever pivotally secured to the bracket, resilient means for urging one end of the lever toward the work rest blade, and positive means for retracting the end of the lever from the work rest blade.

2. In a device of'the class described, the combination of opposed grinding and regulating wheels forming a grinding throat between them, means for actuating the regulating wheel toward and from the grinding wheel, a work rest blade within the grinding throat, pivoted means overlying the work rest blade for retaining work pieces on the work rest blade, and means operable upon actuation of the regulating wheel toward and from the grinding wheel for urging and retracting the pivoted means toward and from the work rest blade.

3. In a. device of the class described, the combination of opposed grinding and regulating wheels forming a grinding throat between them, a work rest blade within the grinding throat adapted to support a work piece, a feed screw, means operable on the screw for advancing and retracting the regulating wheel, a lost motion link operatively connected with the last mentioned means, a rock shaft operatively connected with the lost motion link whereby actuation of the means for advancing and retracting the regulating wheel will cause a movement of the link for partially rotating the rock shaft, and means overlying the work rest blade adapted to be urged toward and from the work rest'blade upon movement of the rock shaft.

4. A centerless grinder for work pieces having their center of gravity outside of the grinding throat, comprising opposed grinding and regulating wheels forming a grind.- ing throat between them, a work rest blade within the throat, a pivoted lever extending into the grinding throat and overlying the work rest blade, and a pivoted retaining member carried by said lever for engaging work pieces of a stepped formation as well as work pieces having a plane cylindrical surface.

5. In a device of the class described, the combination of opposed grinding and regulating wheels "forming a grinding throat between them, a work rest blade within the grinding throat having an inclined top extending toward the regulating wheel, a lever overlying the work rest blade, a retaining blade pivotally carried by the lever for contacting a work piece having an inclined operative surface extending toward the regulating wheel, and means for urging the lever toward the work piece so that the retaining blade may engage the work piece prior to the commencement of the grinding action and for withdrawing the retaining blade from the work piece at the completion of the grinding action.

6. In a device of the class described, the combination of opposed grinding and regulating wheels forming a grinding throat between them, a work rest blade within the grinding throat, means for actuating the regulating wheel toward the grinding wheel, a pivoted lever extending into the grinding throat and overlying the work rest blade, a pivoted retaining member carried by the lever and adapted to contact a work piece on the work rest blade, and means operable upon actuation of the regulating wheel toward-the grinding wheel for urging the retaining member into engagement with the work piece.

'7. In a device of the class described, the

combination of opposed grinding and regulating wheels forming a grinding throat between them, a work rest blade within the grinding throat, pivoted means extending into the grinding throat and overlying the work rest blade, a rock shaft, means for advancing and retract-ing the regulating wheel toward and from the grinding wheel, a crank arm secured to the rock shaft, an adjustable turn buckle having its opposite ends pivotally connected with the c 'ank arm and the. pivoted means overlying the work rest blade, andmeans for rocking the rock shaft when the regulating wheel is advanced-toward and is retracted from the grinding wheel.

'8. A centerless grinder comprising opposed grinding and regulating wheels forming a grinding throat between them, a work rest blade within the grinding throat, a slide supporting the regulating wheel for movement toward and from the grinding wheel, a nut rotatably but non-translatably carried by the slide. a threaded screw having threaded engagen-ient with the nut extending through and beyond the slide, a feed lever secured to the nut, a pin extending from the lever, a lost motion link slidably carried by the slide and adapted to be engaged by the pin, a rock shaft operatively connected with the lost motion link and adapted to be rocked upon engagement of the lost motion link with the pin, and pivotal means extending into the grinding throat operatively connected with the rock shaft.

9. A centerless grinder for 'work pieces having their center of gravity outside of the grinding throat comprising opposed grinding and regulating wheels forming a grinding throat between them, a work rest. blade within the grinding throat for supporting a work piece, a pivotally mounted lever extending into the grinding throat and overlying the work rest blade, a pivotally mounted retaixiing member carried by the lever and having a pair of lugs extendin therefrom for engagement with the work piece and forming a two point contact with said work piece, and yielding means for actuating the lever about its pivot toward the work rest blade equalizing the pressure of the retaining member on all of the points of contact with the work piece.

10. In a centerless grinder, the combination of opposed grinding and: regulating wheels forming a grinding throat between them, a work rest blade within the throat for supporting a work piece, 'a pivotally mounted retaining member within the grindiugthroat overlying the work rest blade, re silient means for urging the retaining member about its pivot into engagement withthe work piece. and positive means for actuating the pivoted lever in the opposite direction against the resilient pressure of the resilient means.

11. In a center-less grinder the combination of opposed grinding and regulating wheels forming a grinding throat between them, a work rest blade within the throat for supporting a work piece, a pivotally mounted retaining member within the grinding throat overlying the work rest blade, resilient means for urging the retaining member about its pivot into engagement with the work piece, positive means for actuating the pivoted lever in the opposite direction against the resilient pressure of the resilient means, and means for actuating the regulating wheel toward the grinding wheel, said means being operatively connected with the positive means for moving the retaining means from the work piece.

12. A centerless grinding machine including a grinding wheel rotatable at a high grinding rate of speed, an opposed regulating wheel rotatable at a slow work controlling rate of speed said wheels being disposed in opposition one to the other and with their adjacent operative faces moving in opposite directions, a work rest blade projecting into the grinding throat intermediate the wheels and having an angled upper surface inclined toward the regulating wheel and means overlying the work rest blade for engagement with a work piece to yieldingly urge the work piece on the work rest blade in the direction of the regulating wheel.

13. A center-less grinding machine including a grinding wheel rotatable at a high grinding rate of speed, an opposed regulating wheel rotatable at a slow work controlling rate of speed, said wheels being disposed in opposition one to the other and with their adjacentoperative faces moving in op posite directions, a work rest blade projecting into the grinding throat intermediate the wheels, having an angled upper surface inclined towardjhe regulating wheel, means overlying the work rest blade for engagement with a work piece to yieldingly urge the work piece on the work rest blade in the direction of the regulating wheel, and means for shifting said member into inoperative position. v

14. A center-less grinding machine including a grinding wheel rotatable at a high grinding rate of speed, an opposed regulating wheel rotatable at a slow work controlling rate of speed, said wheels being disposed in opposition one to the other and with their adjacent operative faces moving in opposite directions, a work rest blade projecting into the grinding throat intermediate the wheels and having an angled upper surface inclined toward the regulating wheel, means overlying the work rest blade for engagement with a work piece to yieldingly urge the work piece on the work rest blade in the direction of the regulating wheel, means for relatively shifting the grinding and regulating wheels to vary the width of throat there-between,

and automatic means for shifting said pressure member in timed relation to the said relative movement of the wheels.

' 15. In a centerless grinder, the combination of a pair of opposed grinding and regulating wheels forming a grinding throat there between, means within the grinding throat supporting a work piece during grinding, means for actuating one of the wheels toward and from the other to effect a stock removal from the work including a manually actuable lever, a retractablebalancing means within the throat for engaging the work piece for forcing andretaining same in engagement with the support means and regulating wheel simultaneously operable with the movement of the wheels b said lever.

16. In a evice of the class described, the combination of a support block, a work sup port' member carried thereby, a bracket extending upwardly from the block, a stop member carried by the bracket to position a work piece relative to the work support and an. overhead pressure member pivotally carried by the bracket engaging the work piece to retain same on the work support.

17. In a device of the 'class described the combination of a support block, a work support member carried thereby, a bracket extending upwardly from the block, a stop member carried by the bracket to position the work piece relative to the work support, an overhead pressure-member pivotally carried by the bracket, and yielding means yieldingly urging the pressure member about its pivot into engagement with the work piece to re: tain same on the supporting member.

18. In a device of the class described the combination of a support block, a work support member carried thereby, a bracket ex tending upwardly from the block, a stop member carried by the bracket to position the work piece relative to the work support, an overhead pressure member pivotally carried by the bracket, yielding means yieldingly urgmg the pressure member about its pivot into engagement with the work piece to retain same on the supporting member and positive means for actuating the pressure memher about its pivot againstthe resistance of the yielding means to release the work piece.

19. In a device of the class described the combination of a support block, a work support member carried thereby, abracket extending upwardly from the block, a stop member carried by the bracket to position the work piece relative to the work support, an overheadpressure member pivotally carried by the bracket, yielding means yieldingly urging the pressure member about its pivot into engagement with the work piece to retain same on the supporting member, positive means for actuatmg the pressure member about its pivot -against. the resistance of the yielding means into engagement with the work piece to retain same on the supporting member, positive means for actuating the pressure member about its pivot against the resistance of the yielding means to release the work piece including an oscillatable lever, an adjustable link between the lever and the pivoted pressure member and a manually operable handle for oscillating the lever.

In testimony whereof I afiix my signature.

' CLEMENT BOOTH. 

